1. Field of the Invention
The present invention relates to a shift lever for operating the transmission of a vehicle and the like.
2. Description of the Related Art
Automatic transmissions for vehicles are preset with multiple shift ranges, and vehicles are provided with manual operating devices for operation of selection of these shift ranges. An example of this type of manual operating device is what is known as a straight-type shift lever device.
A straight-type shift lever device is equipped with a shift lever, which is supported at a preset region of the base end side in the longitudinal direction so as to be turnable around an axis whose axial direction runs substantially in the left-to-right directions of the vehicle. The turning positions of the shift lever are detected by, for example, a position detecting device such as a microswitch, and the electronic control unit (ECU) that controls the automatic transmission is configured to change the shift range of the automatic transmission based on the detection results of the position detecting device.
This type of shift lever is provided with a detent structure that prevents the shift lever from inadvertently moving, for example, from the shift position corresponding to the neutral range that cuts off transmission of the engine driving force to the wheels (hereafter, this position is referred to as “N-position”) to the shift position corresponding to the reverse range that conveys the engine driving force to the wheels and makes the vehicle reverse (hereafter, this position is referred to as “R-position”).
The detent structure is equipped with a detent rod, which is provided in the interior of the shift lever so as to be movable along the longitudinal direction of the shift lever. A detent pin is formed to protrude from the base end side of the longitudinal direction of the detent rod. The detent pin protrudes towards the exterior of the shift lever and is inserted into a detent hole formed in the housing of the shift lever device.
When the shift lever is operated and turned, the detent pin turns with the shift lever in the interior of a shift hole. When the shift lever is in a state where the shift lever has reached the N-position, a protrusion formed in the inner periphery of the detent hole is opposite of the turning direction side of the detent pin when the shift lever turns to the R-position. When trying to turn the shift lever towards the R-position as is in this state, the protrusion interacts with the detent pin and restricts the turning of the detent pin and thus the turning of the shift lever.
A gripping knob provided at the end of the shift lever is equipped with a button. When this button is operated and pressed, the detent rod moves towards the base end side of the shift lever, whereby the detent pin is placed in a condition where it can avoid the aforementioned protrusion. When turning the shift lever from the N-position to the R-position, the protrusion does not interact with the detent pin, and is configured such that the shift lever can be turned from the N-position to the R-position.
The structure of such a shift lever equipped with a button is disclosed in Japanese Patent Application Laid-Open (JP-A) No. 11-151944.
With the shift lever disclosed in JP-A No. 11-151944, a knob button is turnably supported at a supporting axis provided at the inside of the shift knob (knob) at an opening end in the upper portion of the knob. The opening portion of a long rectilinear hole is formed at the side opposite of the pressing surface through the supporting axis of the knob button.
Further, a substantially “<” shaped bent lever is provided at the interior of the shift knob. The lever has a supporting axis set at the bent portion, and is configured so as to be turnable around the center of the supporting axis. A pin is provided at the arm of the opposite side rather than at the crooked portion of the lever. This pin is inserted or placed into the above-described opening portion.
At the same time, one end of a wire corresponding to the above detent rod is latched at the other side at the arm rather than at the bent portion of the lever.
With this shift lever, when the pressing surface of the knob button is pressed, the knob button turns around the supporting axis. When the knob button turns, the inner wall of the opening portion presses and raises a pin and turns the lever around the supporting axis. Due to this, the other arm of the lever is configured to pull the wire.
In the shift lever disclosed in JP-A No. 11-151944, with the increase in the amount of turn of the knob button when the pressing surface of the knob button is pressed, the distance from the center of turning of the knob button to the region where the inner wall of the opening and the pin contact shortens. In other words, the length of the moment arm shortens, whereby it is possible to suppress increases in the necessary pressing force with increases in the amount of turning of the knob button.
Nonetheless, with this type of structure, the rate of change of the distance from the center of turning of the knob button to the region where the inner wall of the opening and the pin contact becomes great, and a sufficient effect cannot be exhibited. Further, in order to suppress increases in the necessary pressing force by shortening the distance from the center of turning of the knob button to the region where the inner wall of the opening and the pin contact, it is necessary to make the distance from the center of turning of the knob button to the region where the inner wall of the opening and the pin contact sufficiently long. This must be done in a state prior to the application of pressing force (i.e., before the knob button turns). For this reason, problems occur such as the size of the knob becoming larger.